William petty: an unlikely influence on karl marx

Introduction 
William Petty (1623-1687) is often cited as being one of the foremost 
innovators in the history of economic thought, and is without doubt one of 
the most extraordinary figures of the 17
th
century. Although he has been 
praised by many significant economists, Karl Marx was particularly vocal. 
He referred to him as “one of the most gifted and original of economic 
investigators” (Roll, 1992:98). It is the aim of this essay to examine why 
Marx held this view, with reference to Petty’s role in developing a labour 
theory of value.
Born into relatively humble beginnings Petty went to sea at the 
young age of 13. After breaking his leg he was put ashore in Normandy, 
France, where he attended university. In Caen he revealed himself to be an 
exceptionally bright student, paying his way by tutoring and trading 
jewellery. He later spent a year acting as secretary to the influential Thomas 
Hobbes
1
in Paris, before proceeding to Oxford. He was appointed professor 
of medicine in 1650, where he was most famous for resurrecting a supposed 
corpse during one of his lectures. He rose rapidly through the ranks at 
Oxford and was involved with the leading scientific minds of the time. He 
was cofounder of the Royal Society of London for the Improvement of 
Natural Knowledge (along with Samuel Hartlib and Robert Boyle). Indeed 
one of his greatest achievements was to introduce rigorous quantitative 
methodology (more commonplace in Boyle’s discipline of physics) into 
1
Thomas Hobbes 1588-1679, philosopher and author of Leviathan. 

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W
ILLIAM 
P
ETTY
:
A
N 
U
NLIKELY 
I
NFLUENCE ON 
K
ARL 
M
ARX
4 
economics. Along with his work in the field of economics, he is particularly 
noted for the role he played in founding the discipline of statistics (along 
with his friend John Gaunt). He later joined the armed forces as chief 
physician to Cromwell’s army in Ireland and made his fortune after he was 
appointed to undertake the Down Survey; a formidable task which he 
completed with distinction
2
. As a result of these efforts he was rewarded 
with substantial amounts of land, including a large estate in Kenmare, 
county Kerry.
Many of his writings were aimed at those in power and were often 
undertaken to address matters of personal concern, particularly the 
protection of the wealth which he had amassed, hence his works on the issue 
of taxation. However, his abilities were not confined to academia. Among 
his more practical projects were the creation of an iron factory on his 
Kenmare estate and the construction of a boat with a new type of double hull 
(which sadly ended at the bottom of the Irish Sea). Recent evidence 
(Aspromourgos, 2005) suggests he was conducting experiments in new types 
of agricultural machinery. He is also accredited with the invention of the 
w.c.
3
Readers can judge for themselves the relative importance of his 
contributions! 
While Petty wrote his works during the mercantilist period of 
economic thought, it is clear that his views were far more advanced than 
many of his contemporaries. Unlike them, he was not so concerned with 
trade balances or hoarding of specie. His acknowledgement of the existence 
of other forms of value (labour in particular) is the main topic of this essay. 
It is my contention that Petty casts a long shadow; that his theories can 
clearly be recognised as the underlying influence behind the value theories 
of Smith, Cantillon, Ricardo and Marx. As a corollary of his investigations 
into value, Petty was the first to explore the notion of surplus. This will also 
be examined (in the light of some new information concerning Petty’s 
involvement in agriculture) in an attempt to answer why Marx regarded 
Petty as one of his most important predecessors, and the “founder of modern 
political economy” (Marx, 1951:15)